Registration Dossier

Diss Factsheets

Environmental fate & pathways

Biodegradation in water: screening tests

Currently viewing:

Administrative data

Link to relevant study record(s)

Reference
Endpoint:
biodegradation in water: ready biodegradability
Type of information:
experimental study
Adequacy of study:
key study
Study period:
17 March 2004 to 15 April 2004
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to guideline
Guideline:
OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)
Version / remarks:
1993
Deviations:
no
Qualifier:
according to guideline
Guideline:
EU Method C.4-D (Determination of the "Ready" Biodegradability - Manometric Respirometry Test)
Version / remarks:
1992
Deviations:
no
Qualifier:
according to guideline
Guideline:
ISO DIS 9408 (Ultimate Aerobic Biodegradability - Method by Determining the Oxygen Demand in a Closed Respirometer)
Version / remarks:
1999
Deviations:
no
GLP compliance:
yes (incl. QA statement)
Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge, non-adapted
Details on inoculum:
- Municipal activated sludge from laboratory wastewater treatment plants fed with municipal sewage.
- Sludge was pre-aerated for about 24 hours before begin of exposition.
- Concentration of dry substance: 30 mg/L.
Duration of test (contact time):
28 d
Initial conc.:
ca. 100 mg/L
Based on:
test mat.
Initial conc.:
2 572 other: mg/g
Based on:
ThOD
Parameter followed for biodegradation estimation:
O2 consumption
Details on study design:
TEST CONDITIONS
- Composition of medium: Inorganic medium
- Test temperature: 22 ± 1°C
- pH: 7.6
- Suspended solids concentration: 30 mg/L
- The test was performed with 7 replicates of the test material (ca. 100 mg/L).

SAMPLING
- Sampling frequency: daily for 28 days

CONTROL AND BLANK SYSTEM
- Inoculum blank: in duplicate containing medium and inoculum only.
- Inhibition control: a single test vessel containing the test material (100.4 mg/L), aniline (100 mg/L) with inoculum and medium.
- Abiotic control: a single test vessel containing the test material (100.8 mg/L), HgCl2 (250 µL) and medium.
- Reference control: a single test vessel containing aniline (100 mg/L) with inoculum and medium.
Reference substance:
aniline
Test performance:
VALIDITY CRITERIA
- Deviation of the degradation degree of the test material in the plateau phase < 20%: yes
- Degradation degree of the reference substance > 60% after 14 days: yes
- Degradation degree in the inhibition control > 25% after 14 days: yes
- Oxygen demand in the blank control < 60 mg/L at the end of the test: yes
- pH values in the test assays ranged from pH 6 to 8,5 at the end of the test: yes
- The test is valid: yes
Key result
Parameter:
% degradation (O2 consumption)
Value:
< 10
Sampling time:
28 d
Details on results:
- Percentage biodegradation values for all conditions can be seen in Table 1.
Results with reference substance:
- After 14 days the reference material had 76 % biodegradation.
- After 28 days the reference material had 80 % biodegradation.
- This means the reference material was acceptable according to the validity criteria of the test.

Table 1: Biodegradation in relation to the ThOD [%]

Days

Percentage Biodegradation in Relation to the ThOD (%)

RS

IH

PC

TM1

TM2

TM3

TM4

TM5

TM6

TM7

0

0

0

0

0

0

0

0

0

0

0

1

-2

-1

0

0

0

0

1

-1

0

0

2

-2

-1

0

0

1

0

1

-1

0

1

3

-1

0

0

0

0

0

1

-1

0

0

4

19

1

0

0

0

0

0

-2

0

0

5

56

23

0

-1

0

-1

0

-2

-1

-1

6

59

29

0

-1

-1

-1

0

-2

-1

-1

7

64

33

0

-1

-1

-1

0

-2

-1

-1

8

65

34

0

-1

0

-1

0

-2

-1

-1

9

67

35

0

-1

0

-1

0

-2

-1

-1

10

73

35

0

0

0

-1

0

-2

-1

-1

11

75

36

0

0

0

-1

0

-2

-1

-1

12

76

36

0

-1

0

-1

0

-2

-2

-1

13

76

36

0

-1

-1

-2

0

-2

-2

-1

14

76

36

0

-1

0

-2

0

-2

-2

-1

15

77

36

0

0

0

-1

0

-2

-2

-1

16

76

36

1

-1

-1

-2

-1

-3

-2

-2

17

77

36

1

-1

-1

-2

-1

-3

-2

-2

18

77

37

1

-1

-1

-2

-1

-3

-2

-2

19

78

37

1

-1

-1

-2

-1

-2

-2

-1

20

79

37

1

0

-1

-2

0

-2

-2

-1

21

78

37

2

-1

-2

-2

-1

-3

-2

-2

22

78

37

2

-1

-2

-2

-1

-3

-2

-2

23

79

37

2

-1

-2

-2

-1

-3

-2

-2

24

79

38

2

0

-2

-2

-1

-3

-2

-2

25

79

38

2

0

-2

-2

-1

-2

-2

-2

26

80

38

2

0

-2

-2

-1

-2

-2

-2

27

79

38

2

-1

-3

-2

-1

-3

-2

-2

28

80

38

2

-1

-3

-2

-1

-3

-2

-2

RS = reference substance, IH = inhibition control, PC = abiotic control, TM = test material

Validity criteria fulfilled:
yes
Interpretation of results:
not readily biodegradable
Conclusions:
Under the conditions of this study the test material was not readily biodegradable.
Executive summary:

The ready biodegradability of the test material was investigated in accordance with the standardised guidelines OECD 301F, EU Method C.4-D and ISO 9408, under GLP conditions.

Municipal activated sludge from laboratory wastewater treatment plants fed with municipal sewage was used for the test at a concentration of dry substance 30 mg/L.

After 28 days the test material exhibited less than 10% biodegradation. The positive control exhibited 76% biodegradation after 14 days and 80% biodegradation after 28 days. All of the validity criteria of the test were met.

Under the conditions of this study the test material was not readily biodegradable.

Description of key information

Under the conditions of this study the test material was not readily biodegradable.

Key value for chemical safety assessment

Biodegradation in water:
under test conditions no biodegradation observed
Type of water:
freshwater

Additional information

The potential biodegradation of the test material was investigated in accordance with the standardised guidelines OECD 301F, EU Method C.4-D and ISO 9408, under GLP conditions. The study was awarded a reliability score of 1 in accordance with the criteria set forth by Klimisch et al. (1997).

Municipal activated sludge from laboratory wastewater treatment plants fed with municipal sewage was used for the test at a concentration of dry substance 30 mg/L.

After 28 days the test material exhibited less than 10 % biodegradation. The positive control exhibited 76 % biodegradation after 14 days and 80 % biodegradation after 28 days. All of the validity criteria of the test were met.

Under the conditions of this study the test material was not readily biodegradable.